Pine nut syndrome, or “pine mouth,” is an uncommon type of dysgeusia that causes a metallic taste within about two days after eating pine nuts—and this taste can linger for up to a month later.

In contrast, pine nuts can cause a taste disturbance known as "pine mouth," making them less appealing to some folks. Walnuts ...

You may also experience a metallic mouth up to 4 weeks after eating pine nuts. This temporary sensation, which is not an allergic reaction, is sometimes called pine nut syndrome or pine mouth.